When Jared Sullinger slipped to the Celtics at No. 21 overall, many pundits quickly declared him the steal of the 2012 NBA draft. And as much as you can make such a declaration 10 games into this season, they were right.

After averaging 17.2 points and 10.2 boards as an Ohio State sophomore, Sullinger recorded the first double-double of his NBA career on Saturday afternoon, amassing 12 points (5-8 FG, 2-2 FT) and 11 rebounds in 26 minutes off the bench in the C’s 107-89 victory against the Atlantic Division rival Raptors.

“I’m used to having double-doubles,” he said, “so it feels good to carry it over to the next level.”

Sullinger’s performance came on the heels of playing a season-low eight minutes on Thursday, when he was benched after giving up an offensive rebound in the C’s 102-97 loss to the Nets.

“He knows his place,” said Celtics coach Doc Rivers, whose first-year players rarely see the floor. “I think he wasn’t happy about not playing against Brooklyn … but he just knows how to play. He’s a calming effect at times when you put him in, and I don’t think I’ve ever said that about a rookie. It’s nice to have that.”

Sullinger raised his season averages to 3.9 points (51.6 FG%, 100.0 FT%) and 4.1 rebounds in 16 boards a night, but more importantly the Celtics earned a sixth win in their last eight games, and he’s contributed to all of them. When you look at all 14 bigs drafted in the first round, Sullinger is the most productive on any winning team.

“I’m just doing my job,” said Sullinger, who faces No. 9 overall pick Andre Drummond on Sunday. “I could care less. It put a chip on my shoulder, but I could care less how that goes. I’m just out there playing basketball. It’s a great situation. I could’ve been on some other team, worrying about not winning, instead of just playing basketball and being able to have a legitimate shot at winning every night, so it’s a blessing to be here, honestly.”

With the exception of No. 1 overall selection Anthony Davis, nobody has outperformed Sullinger, and certainly no other rookie big man has produced like him for a team that expects to contend for an NBA title. Also, note how he measures up to others that were on the Celtics radar: White, Terrence Jones, Nicholson and Perry Jones.

And, of course, those numbers don’t even begin to take into account the nuances of Sullinger’s game.

“When you’re playing with him and as his teammate, his dives, his rolls, him getting [Jason Terry] open looks, stuff like that — little small things that’s not going to show up on your yellow pad — the small things that he does makes us better,” said Kevin Garnett, who also rarely heaps praise on a rookie. “In order for us to be better and in this process of getting better, everybody has to do those small things, so you know what? On your yellow pad, he’s not that big of a deal. Tonight, obviously, for your yellow pad, he did a great job, but overall Sully’s doing small things along with Chris [Wilcox] and all the other guys that’s making us come out this funk that we were in.”